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Practice English Speaking&Listening with: Fear: Replacing Memories

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INTRODUCTION: Welcome toSpeaking of Science”, the

National Institute of Mental Health presents a series of conversations with innovative

researchers working in a wide range of disciplines to pave the way for the prevention, recovery,

and cure of mental illness.

NARRATOR: We all have difficult sometimes

painful memories stored in our minds. Memories most of us are able to come to terms with,

but for some people the trauma of experiencing danger, violence, or panic can create a debilitating

disorder. What if fear memories could be rewritten? DR. LEDOUX: All of this research was based

on systemic manipulations of the brain. NARRATOR: Dr. Joseph LeDoux is a Professor

of Science at New York University and serves as Principal Director for the NIMH funded

Center for the Neuroscience of Fear and Anxiety. He is part of a team that has found a way

to block fear memories through a process called reconsolidation. During a recent visit to

the NIMH campus in Bethesda, Dr. LeDoux explained the key to reconsolidation is understanding

how memories are formed in the first place. DR. LEDOUX: Each time you form a memory your

brain begins to form that memory in a temporary way that can be interfered with if nothing

else happens. So you have to convert a temporary memory into a long term memory in order to

have that memory at some time in the future. NARRATOR: In 1999 a study from the LeDoux

team showed the ability to block the consolidation of fear memories by injecting Protein synthesis

inhibitors to stop growth of certain cells in the amygdala, the brains fear hub.

DR. LEDOUX: So that led Graham Nader who was in my lab at the time say well can we do the

same with reconsolidation? Which means, instead of giving the protein synthesis inhibitor

after learning and blocking consolidation, you give it after the retrieval of a previously

consolidated memory? So you form the memory, the animal now has a long term memory and

then at some point after that memory is fully established, you give the rat the tone which

retrieves the memory and then you give the protein synthesis inhibitor and then you test

the animal the next day and the memory is no longer there. Its like a person who

goes to trial to testify about a crime and instead of testifying about what they witnessed

on that day they testify about what they read in the newspaper. Because each time you take

a memory out of a newspaper reading did, you restore it and the information gets stored as a new

memory. So the bottom line of all this research is--your memory is only as good as your last

memory. NARRATOR: Perhaps the greatest potential for

therapeutic application is with post traumatic stress disorder patients.

DR. LEDOUX: Where a patient with intrusive memories could be through the aid of a therapist

and the aid of proper manipulations such as a drug that is safe to use with humans. The

patient could be encouraged to retrieve the traumatic memory, given the manipulation and

presumably the memory will be weakened at a later point.

NARRATOR: In December, a new study was published in Nature from a larger NYU research team

that showed a drug-free method of replacing fear memories in people using exposure training.

Dr. LeDoux acknowledges ethical questions when it comes to the science of altering memories.

DR. LEDOUX: I understand why people worry about that because memories are treated as

sacrosanct; we are our memories in many ways. We have to remember who we are to be that

person from day to day. But one thing we have to realize is just how much we manipulate

memory as part of life. Every time we watch an ad for a product our memory is being manipulated,

every time a student goes to class his or her memory is being manipulated, every time

you have a social interaction with a person you try to create a good impression which

is basically a memory. Once we put it into that context the idea that you might use memory

manipulation to help people maybe doesnt seem so malevolent.

The Description of Fear: Replacing Memories